System of regulation for electric motors.



No. 722,563. PATENTED MAR; 10, 1903.

P. T. COLLINS. SYSTEM OF- REGULATION FOR ELECTRIC MOTORS.

APPLICATION FILED JULY 21,4900. RENEWED AUG. 20, 1902.

I0 MODEL.

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UNITED STATES PATENT OFFICE.

PATRICK J. COLLINS, OF SORANTON PENNSYLVANIA, ASSIGNOR, BY MESNE ASSIGNMENTS, TO RICHARD J. BOURKE, TRUSTEE, OF SCRANTON, PENN- SYLVANIA.

SYSTEM OF REGULATION FOR ELECTRIC MOTORS.

SPECIFICATION forming part of Letters Patent No. 722,563, dated March 10, 1903.

Original application filed December 18, 1899, Serial No. 740,715. Divided and this application filed July 21,1900. Renewed August 20, 1902. Serial No. 120,321. (No model.)

T- all whom it may concern:

Be it known that I, PATRICK J. OoLLINs, a citizen of the United States, residing at Scranton, in the county of Lackawanna and State of Pennsylvania, have invented certain new and useful Improvements in Systems of Regulation for Electric Motors, of which the following is a specification.

My invention relates to the improved means for controlling the speeds of one or more pairs of armatures illustrated in my application, Serial No. 740,715, filed December 18, 1899, (Patent No. 656,389, dated August 21, 1900,) of which this application is a division.

The invention comprises an arrangement of circuits and connections by means of which the armatures may be operated at the same speed, or by the turning of a single switchlever the speeds of the armatures may be va- 2o ried relatively-to each other, so that as one armature increases in speed the speed of the other will decrease. This arrangement is desirable for automobile work in which independent armatures are geared to the driving- 2 5 wheels on the opposite sides of the vehicle and said armatures are varied in speed relatively to each other for the purpose of steering.

In the accompanying diagram, which illustrates my invention, 1 and 2 represent a pair of armatures, and 3 and 4 represent the corresponding field coils. The armatures, as shown, are connected in series with each other and to the battery 5 through a reversing switch 6 and mains 7 and 8. By means of 3 5 the reversing-switch the direction of rotation of the armatures may be controlled in the usual manner and the speeds of both armatures may be simultaneously increased or decreased byasuitable controller. (Not shown.)

The fields, as shown in the drawing, are connected in series with each other, as indicated by circuit 9, 10, and 11. A resistance-coil 12 is connected at one end to the wire 11, and wires 13, 14, and 15 connect contact-points A,

5 B, and O of the steering-switch 16 with different points in the resistance-coil. A wire 17 connects the semicircular contact piece D with the wire 10, connected to the inner terminal of the field-coil 4. The switch-arm contacts I, J, and K are connected by wires 18 is provided with suitable metallic ends 19 and 20, adapted to connect the inner semicircular contact-pieces D and E with the concentric contact-pieces. It will be seen that if the arm is moved from the central position shown onto the contact-piece O the entire resistance 12 will be thrown in shunt to the field 4 through the wires 15 and 17. This will weaken said field and cause the armature 2 to run faster than before. The continued movement of the arm will shunt the current through the contact-piece B, wire 14, and a portion of the resistance 12 will be cut out, thus still further weakening the field, and the movement of the arm onto the contact-pieceA will cause the current to traverse the wire 13 and a still smaller section of the resistance,thus again weakening the field.

A resistance 21 is connected in a similar way by wires 22, 23, and 24 to contact-points F, G, and H, respectively, and the inner termi- 7o nal ot the field-coil 3 is connected by a wire 25 to the semicircular contact-plate E. The movement of the end 20 of the arm, therefore, over said contact-points H, G, and F in succession will correspondingly weaken the field 7 5 3 and cause the armature 1 to rotate faster.

In order to strengthen one field and simultaneously weaken the other, I provide upon the switch a series of contact-pieces I, J, and. K, which are arranged diametrically opposite to the contact-pieces A, B, and 0, respectively, and a similar series of contact-pieces L, M, and N, which are arranged respectively opposite to the contacts F, G, andH. The

5 26, 27, and 28 to different points of the fieldcoil 3, and the contact-pieces L, M, and N are connected by wires 29, 30, and 31 to different points of the field-coil 4.

When the arm 18 is turned into the position indicated in dotted lines, the bridge-piece 19 will connect the contact-pieces O and D and a portion of the current will be shunted around the field 4, weakening the latter in the manner previously described, and the field 3 will be strengthened by reason of the short-circuiting of the coils upon the field between the points of connection of the wire 28 and the wire 10, the current passing through I In motor-vehicles this arrangement is desirsaid wire 28, contact-piece K, bridge-piece 20, contact E, and wire 25 to the wire 10. This short-circuiting of a section of the field 3 reduces the resistance of the field and permits a larger quantity of current to circulate in the remaining coils, thereby strengthening the field. It will be seen that the movement of the arm 18 onto the contact-piece J will short-circuit a greater portion of the field 3 through the wire 27 and that the still further movement will shortcircuit a larger section of the field-coil through the wire 26, and the increased volume of current which is permitted to pass by reason of the reduction in resistance will increase the strength of the field 3. It will be clear without further description that the movement of the arm in the opposite direction will cause an increase in the strength of the field 4 and a corresponding decrease in the strength of the field 3 and that while the arm is in the central position (shown in full lines in the figure) the field strengths will remain alike.

The switch-arm is turned by means of a lever 32, and it will be apparent from the fore-- going description that a movement of this lever to the right will cause an increase in the speed of the armature 1 upon the left and a decrease in the speed of the armature 2 upon the right, while a movement of the lever to the left will cause an increase in the speed of the right-hand armature and a decrease in the speed of the left-hand armature. When the lever is held in the central position, both armatures will turn at the same speed.

able, as it is only necessary to swing the lever in the direction in which it is desired to go in order to cause the armatures to turn relatively to each other at the proper speeds to steer the vehicle.

It will be apparent that several pairs of armatures may be controlled simultaneously by the same switch, with a similar arrangement of circuits connected to each pair of motors. The armatures may be arranged within separate field-casings or within a single field-casing, as illustrated in my application hereinbefore referred to.

Having described my invention, what I claim, and desire to secure by Letters Patent of the United States, is

The combination with a pair of independent armatures and separate sectional fieldwindings for each armature, of a graduated resistance arranged in shunt to each fieldwinding, a switch and connections leading therefrom to successive points in said windings and resistances, said switch and connections being so arranged that when the switcharm is turned in either direction from the neutral point, the resistance in shunt to one field-winding will be decreased and the resistance of the other field-winding will be decreased.

In testimony whereof I affiX my signature in presence of two witnesses.

PATRICK J. COLLINS.

"Witnesses:

ROBERT WATSON, GEO. O. YOCUM. 

